1. High-energy photon and particle emission from GRBs/SNe Xiang-Yu Wang Nanjing University, China Co-authors: Zhuo Li (Weizmann), Soebur Razzaque (PennState), Peter Meszaros (PennState), Zi-Gao Dai (NJU) 2008 Nanjing GRB conference June 23-27, 2008; Nanjing, China

2. Electrons- Shock acceleration: ~10 TeV Protons (or nuclei)- 1) Shock acceleration (e.g. Waxman 1995; Vietri 1995) Candidate source of ultra-high energy cosmic rays (UHECRs) 2) Neutrinos from photo-meson and pp processes (e.g. Waxman & Bahcall 1997; Bottcher & Dermer 1998) Particle acceleration in GRB shocks X-ray afterglows modeling e.g. Li & Waxman 2006 Obs. Channel: High-E photons can probe electrons Obs. Channel: High-energy particles (UHECRS, Neutrinos)

3. Outline High-energy gamma-ray emission from GRBs GRB/Hypernova model for UHECRs UHE nuclei: acceleration and survival in the sources Prompt TeV neutrino emission from sub-photosphere shocks of GRBs

4. I. High-energy gamma-rays Two basic mechanisms 1)Leptonic process: Electron IC 2)Hadronic process GRB930131 GRB940217

5. Leptonic process- inverse Compton scattering Internal shock IC: e.g. Pilla & Loeb 1998; Razzaque et al. 2004; Gupta & Zhang 2007 External shock IC reverse shock IC: e.g. Meszaros, et al. 94; Wang et al. 01; Granot & Guetta 03 forward shock IC: e.g.Meszaros & Rees 94; Dermer et al. 00; Zhang & Meszaros 01 Credit P. Meszaros

6. 1. IC emission from very early external shocks Shocked shell Shocked ISM Cold ISM Cold shell pressure FS RS CD 1)(rr) 2)(ff) 3)(fr) 4)(rf) Four IC processes (Wang, Dai & Lu 2001 ApJ,556, 1010) At deceleration radius, T_obs~10-100 s Forward shock---Reverse shock structure is developed

7. Energy spectra--- At sub-GeV to GeV energies, the SSC of reverse shock is dominant; at higher energies, the Combined IC or SSC of forward shock becomes increasingly dominated Reverse shock SSC (r,f) IC (f,r) IC Forward shock SSC Log(E/keV) GLAST 5 photons sensitivity (Wang, Dai & Lu 2001 ApJ,556, 1010)

8. One GeV burst with very hard spectrum- leptonic or hadronic process? − 18 s – 14 s 14 s – 47 s 47 s – 80 s 80 s – 113 s 113 s – 211 s Gonzalez et al. 03: Hadronic model Leptonic IC model: Granot & Guetta 03 Pe’er & Waxman 04 Wang X Y et al. 05 GRB941017 Wang X Y et al. 05, A&A, 439,957 Reverse shock SSC ISM medium environment

9. ~30%-50% early afterglow have x-ray flares, Swift discovery Flare light curves: rapid rise and decay <<1 Afterglow decay consistent with a single power-law before and after the flare 2. High-energy photons from X-ray flares Burrows et al. 2005 Falcone et al. 2006 amplitude: ~500 times above the underlying afterglow GRB050502B X-ray flares occur inside the deceleration radius of the afterglow shock X-ray flares: late-time central engine activity

10. IC between X-ray flare photons and afterglow electrons (Wang, Li & Meszaros 2006) Cnetral engine X-ray flare photons Forward shock region Cartoon X-ray flare photons illuminate the afterglow shock electrons from inside also see Fan & Piran 2006: unseen UV photons

11. IC GeV flare fluence-An estimate So most energy of the newly shock electrons will be lost into IC emission X-ray flare peak energy

12. Temporal behavior of the IC emission Not exactly correlated with the X-ray flare light curves. IC emission will be lengthened by the afterglow shock angular spreading time and the anisotropic IC effect Self-IC of flares, peak at lower energies Wang, Li & Meszaros 2006 In external shock model for x-ray flares

13. What could GLAST tell us?  Origin of GeV photons (both prompt and delayed): spectral and temporal properties  Magnetic field in the shocks:  Maximum energy of the shock accelerated electrons :  … Launched 11/06/2008

14. high-E protons or nuclei in GRB shocks? Hypernova model for UHECRs High-energy nuclei in UHECRs Neutrinos-

15. CR spectrum knee ankle -2.7 -3.1 GZK cutoff Observed by HiRes and Auger

16. Galactic CR--Extra-galactic CR transition CRs below the knee: protons accelerated by Galactic SNR Galactic CRs may extent up to >1e17eV: high-z nuclei Transition position from GCR to EGCR: still controversial 1) ankle: EGCRs start at E>1e19 eV require GCRs extending to ~1e19 eV (e.g. Budnik et al. 07) 2) the second knee: E~6e17 eV where the composition changes significantly (HiRes data) 2nd knee e.g. Berezinsky et al. 06 *

17. Source models for EGCRs AGNs, radio galaxies (Biermann….) GRBs (waxman 05; Vietri; Dermer) Cluster of galaxies Magnetar (Ghisellini’s talk) … Semi-relativistic Hypernovae: ? large explosion energy SN (E=3- 5e52erg) with significant mildly- relativistic ejecta 3C 296 GRB Wang et al.2007

18. Hypernova prototype – SN1998bw: an unusual SN In the error box of GRB980425 1)Type Ic SN 2)High peak luminosity, broad emission lines -> modelling require large (E=3-5e52erg) explosion energy (E=3-5e52erg) Normal SN: E=1e51 erg

19. GRB980425: gamma-ray, radio & x-ray observations sub-energetic GRB—GRB980425: E~1e48 erg (d=38 Mpc) Radio afterglow modeling: E>1e49 erg, \Gamma~1-2 X-ray afterglow: E~5e49 erg, \beta=0.8 (Waxman 2004) Mildly relativistic ejecta component

20. Other hypernovae/sub-energetic GRBs SN2003lw/GRB031203 SN2006aj/GRB060218  prompt thermal x-ray emission—mildly relativistic SN shock breakout from stellar wind Campana et al. 06 Waxman, Meszaros, Campana 07

21. CR spectrum — Hypernova energy distribution with velocity Semi-relativistic hypernova: high velocity ejecta with significant energy is essential Normal SN Very steep distribution -> negligible contribution to high-energy CRs Berezhko & Volk 04 Wang, Soeb, Meszaros, Dai 07

22. The maximum energy of accelerated particles 1) Type Ib/c SN expanding into the stellar wind, Wolf-Rayet star 2) equipartition magnetic field B, both upstream and downstream Protons can be accelerated to >=1e19 eV Maximum energy: Hillas 84

23. The CR flux level  energetics 1)Extra-galactic hypernova explosion rate 2)average energy per hypernova event Normal Ib/c SN rate: sub-energetic GRB rate: Hypernova (v=0.1c) Normal GRBs Rate (z=0) ~500 ~1 ~1 kinetic energy 3-5e52 erg 1e53-1e54erg Compare with normal GRBs The required rate : Soderberg et al. 06; Liang et al. 06

24. UHECR chemical composition--Auger result Elongation Rate measured over two decades of energy Unger et al. 07, ICRC X_max Possible presence of nuclei in UHECRs

25. Origin and survival of UHE nuclei GRB GRB Internal shock (Waxman 1995) External shock (Vietri 95, Dermer et al. 01) Hypernova remnant: mildly-relativistic ejecta Hypernova remnant: mildly-relativistic ejecta Internal shock External shock Relativistic outflow Central engine Wang, Razzaque & Meszaros 08

26. Speculation on the origin of nuclei 1) GRB internal shock 2) GRB external shock and hypernova models nuclei from swept stellar wind O Fe O C He O C at the base, r=1e6-7cm T=1-10MeV fully photo-disintegrated Mixing of surrounding material into the jet

27. Survival of UHE nuclei photo-disintegration or photopion energy loss rate: Condition for survival:

28. Survival of UHE nuclei – internal shock

29. Survival of UHE nuclei – External shock Optical depth for photo-disintegration Maximum particle energy Constant density medium Wind medium Photon source: Early x-ray afterglow emission

30. Optical depth for photo-disintegration Maximum particle energy Survival of UHE nuclei – Hypernova remnants

31. Survival of UHE nuclei Conclusions: survival of heavy nuclei in the following sources GRB internal shock – give constraints GRB external shock -ok Hypernova remnant -ok

32. GRB Neutrinos He/CO star H envelope Buried shocks No  -ray emission Razzaque, Meszaros & Waxman, PRD ‘03 Precursor ’s Internal shocks Prompt  -ray (GRB) Waxman & Bahcall ’97 Murase & Nagataki 07 Burst ’s External shocks Afterglow X,UV,O Waxman & Bahcall ‘00 Afterglow ’s  CR PeV EeV TeV

33. Neutrino emission during the prompt phase Waxman & Bahcall (1997), Dermer & Atoyan 03 Murase &Nagataki 06 Broken power-law spectrum for radiation photons

34. photosphere component in the prompt emission Motivation: prompt thermal emission Advantages of Thermal component : The “death line” problem; clustering of peak energies; Amati relation Hybrid model: thermal (sub- photosphere) + non-thermal (further out, optically thin shocks) Origin of thermal emission: sub-photosphere internal shocks (Rees & Meszaros 05) Ryde 05 Rees & Meszaros 05; Pe’er et al. 06

35. Prompt neutrinos associated with dissipative photosphere Diffuse neutrino spectrum Inverse cooling time for protons Wang & Dai 08

36. Promising prospect for GRB high-energy process : Multi-messenger observation era Photons– GLAST, HESS, HAWC… Neutrinos-- Icecube, KM^3, ANITA… Cosmic Rays-- Pierre Auger South, North,… 2008 2011 2007-